Shadow users can be tricky to depict believably, but I can imagine darkness fillling the room as the dark priest is pushed across the final treshold, spreads his wings and calmy tells his tormentor: "You underestimate my power. DO NOT TAKE ME FOR SOME CONJURER OF CHEAP TRICKS!"

Tinfoilhat-theorycrafting:The Lich King prepared the females of Valkyrion to be host bodies. The Valkyr are broken spirithealers that he enslaved in the spirit realm, and sent into the willing hosts on the mortal realm. Through the Lich King they gained the ability to travel between the planes, but their ressurections were corrupted and weakened.

They joined Sylvanas and the Forsaken to use their powers to bring back those who died who they would have returned as Spirit Healers, but who now are dead because they were gone, and to serve those who have shared their fate.